• The Journal of Advanced Prosthodontics
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• v.6 no.3
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• pp.215-223
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• 2014

PURPOSE. This study aimed to develop a copper-aluminium-nickel alloy which has properties comparable to that of dental alloys used for dental post and core applications with the reasonable cost. MATERIALS AND METHODS. Sixteen groups of experimental copper alloys with variants of 3, 6, 9, 12 wt% Al and 0, 2, 4, 6 wt% Ni were prepared and casted. Their properties were tested and evaluated. The data of thermal, physical, and mechanical properties were analyzed using the two-way ANOVA and Tukey's test (${\alpha}$=0.05). The alloy toxicity was evaluated according to the ISO standard. RESULTS. The solidus and liquidus points of experimental alloys ranged from $1023^{\circ}C$ to $1113^{\circ}C$ and increased as the nickel content increased. The highest ultimate tensile strength ($595.9{\pm}14.2$ MPa) was shown in the Cu-12Al-4Ni alloy. The tensile strength was increased as the both elements increased. Alloys with 3-6 wt% Al exhibited a small amount of 0.2% proof strength. Accordingly, the Cu-9Al-2Ni and Cu-9Al-4Ni alloys not only demonstrated an appropriate modulus of elasticity ($113.9{\pm}8.0$ and $122.8{\pm}11.3$ GPa, respectively), but also had a value of 0.2% proof strength ($190.8{\pm}4.8$ and $198.2{\pm}3.4$ MPa, respectively), which complied with the ISO standard requirement (>180 MPa). Alloys with the highest contents of nickel (6 wt% Ni) revealed a widespread decolourisation zone (5.0-5.9 mm), which correspondingly produced the largest cell response, equating positive control. CONCLUSION. The copper alloys fused with 9 wt% Al and 2-4 wt% Ni can be considered for a potential use as dental post and core applications.

• Applied Microscopy
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• v.45 no.1
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• pp.9-15
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• 2015

In the present study, microstructural evolution in CuCrFeNi, CuCrFeNiMn, and CuCrFeNiMnAl alloys has been investigated. The as-cast CuCrFeNi alloy consists of a single fcc phase with the lattice parameter of 0.358 nm, while the as-cast CuCrFeNiMn alloy consists of (bcc+fcc1+fcc2) phases with lattice parameters of 0.287 nm, 0.366 nm, and 0.361 nm. The heat treatment of the cast CuCrFeNiMn alloy results in the different type of microstructure depending on the heat treatment temperature. At $900^{\circ}C$ a new thermodynamically stable phase appears instead of the bcc solid solution phase, while at $1,000^{\circ}C$, the heat treated microstructure is almost same as that in the as-cast state. The addition of Al in CuCrFeNiMn alloy changes the constituent phases from (fcc1+fcc2+bcc) to (bcc1+bcc2).

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3239-3244
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• 2011

Dinuclear Ni(II)-thiophene halides, which contain linear bridging thienylenes, trans,trans-[$(PR_3)_2$(X)Ni-Y-Ni(X)$(PR_3)_2$] {X = Cl, Br; $H_2Y$ = 5,5'-dichloro-2,2'-bithiophene ($H_2bth$); $H_2tth$ = 5,5"-dichloro-2,2':5',2''-terthiophene ($H_2tth$)} were prepared by the oxidative addition of dihalobithiophene ($H_2bth$) or dihaloterthiophene ($H_2tth$) to [$Ni(COD)_2$] in the presence of tertiary phosphines. Subsequent reactions of $NaN_3$ with the dinuclear Ni(II)-thiophene chlorides gave the corresponding Ni(II)-azido complexes, trans,trans-[$(PR_3)_2(N_3)$Ni-Y-Ni$(N_3)(PR_3)_2$], whose reactivity toward trimethylsilyl pseudohalides such as trimethylsilyl isothiocyanates and cyanides was investigated. In addition, the reaction of trans-[$BrNi(PEt_3)_2-C_4H_2S-C_4H_2S$-CHO], a thienyl Ni(II) complex containing a terminal aldehyde group, with phosphonium ylide was examined.

• Proceedings of the KWS Conference
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• 1997.05a
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• pp.102-104
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• 1997

• Proceedings of the KWS Conference
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• 1996.10a
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• pp.153-159
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• 1996

• 한국전기화학회:학술대회논문집
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• 2003.04a
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• pp.9-9
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• 2003

• Applied Chemistry for Engineering
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• v.17 no.4
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• pp.349-356
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• 2006

We have investigated adsorption and desorption properties of CO adsorption on silica supported Ru/Ni alloys at various Ru/Ni mole content ratio as well as CO partial pressures using Fourier transform infrared spectrometer (FT-IR). For Ru-$SiO_{2}$ sample, four bands were observed at $2080.0cm^{-1}$, $2021.0{\sim}2030.7cm^{-1}$, $1778.9{\sim}1799.3cm^{-1}$, $1623.8cm^{-1}$ on adsorption and three bands were observed at $2138.7cm^{-1}$, $2069.3cm^{-1}$, $1988.3{\sim}2030.7cm^{-1}$ on vacumn desorption. For Ni-$SiO_{2}$ sample, four bands were observed at $2057.7cm^{-1}$, $2019.1{\sim}2040.3cm^{-1}$, $1862.9{\sim}1868.7cm^{-1}$, $1625.7cm^{-1}$ on adsorption and two bands were observed at $2009.5{\sim}2040.3cm^{-1}$, $1828.4{\sim}1868.7cm^{-1}$ on vacumn desorption. These absorption bands correspond with those of the previous reports approximately. For Ru/Ni(9/1, 8/2, 7/3, 6/4, 5/5; mole content ratio)-$SiO_{2}$ samples, three bands were observed at $2001.8{\sim}2057.7cm^{-1}$, $1812.8{\sim}1926.5cm^{-1}$, $1623.8{\sim}1625.7cm^{-1}$ on adsorption and three bands were observed at $2140.6cm^{-1}$, $2073.1cm^{-1}$, $1969.0{\sim}2057.7cm^{-1}$ on vacumn desorption. The spectrum pattern observed for Ru/Ni-$SiO_{2}$ sample at 9/1 Ru/Ni mole content ratio on CO adsorption and on vacumn desorption is almost like the spectrum pattern observed for Ru-$SiO_{2}$ sample. But the spectrum patterns observed for Ru/Ni-$SiO_{2}$ samples under 8/2 Ru/Ni mole content ratio on CO adsorption and vacumn desorption are almost like the pattern observed for $Ni-SiO_{2}$ sample. It may be suggested surfaces of alloy clusters on the Ru/Ni-$SiO_{2}$ samples contain more Ni components than the mole content ratio of the sample considering the above phenomena. With Ru/Ni-$SiO_{2}$ samples the absorption band shifts may be ascribed to variations of surface concentration, strain variation due to atomic size difference, variation of bonding energy and electronic densities, and changes of surface geometries according to surface concentration variation. Studies for CO adsorption on Ru/Ni alloy cluster surface by LEED and Auger spectroscopy, interation between Ru/Ni alloy cluster and $SiO_{2}$, and MO calculation for the system would be needed to look into the phenomena.

• Bulletin of the Korean Chemical Society
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• v.18 no.9
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• pp.1022-1028
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• 1997

The reaction between Ni(Ⅱ) and sodium salt of 5,6-dihydro-1,4-dithiin-2,3-dithiolate (DDDT2-) in the presence of oxygen results in the formation of Ni(Ⅲ) species, Ni(DDDT)2-, which is isolated as tetraalkylammonium salt. The same reaction performed in the absence of oxygen yields dianionic Ni(Ⅱ) species, Ni(DDDT)22-, which is also isolated as the tetraethylammonium salt. The bis(5,6-dihydro-1,4-dithiin-2,3-dithiolato) nickelate (Ⅱ) dianion, Ni(DDDT)22-, reacts with methyl iodide to yield unusually stable bis(methylthio)dithiolene complex, Ni(CH3)2C8H8S8. All the isolated dithiolato-nickel(Ⅱ) and nickel(Ⅲ) complexes are characterized by 1H NMR, UV/Vis, IR and mass spectroscopic methods. The internal redox reaction of the nickel(Ⅱ)-dithiolate has been studied by spectro-electrochemical method and the results were compared with those of other metal-dithiolenes. The alkylated nickel(dithiolene) complex presumably undergoes cis-trans isomerization reaction in solution, judging from the experimental results of variable-temperature 1H NMR measurements.

• Journal of Hydrogen and New Energy
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• v.13 no.3
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• pp.197-203
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• 2002

The main emphasis of this study was to find an new hydrogen absorbing alloy such as Mg-Ti-Ni-H systems, and to investigate their hydrogenation properties. ($Mg_9Ti_x$)-10, 20wt%Ni-Hx systems were prepared by hydrogen induced mechanical alloying(HIMA) using Mg and Ni chips and sponge Ti. The particles synthesized were characterized by X-ray diffraction, and their morphologies were observed by means of scanning electron microscopy(SEM) with energy dispersive spectrometry (EDS). In addition, the crystal structures were analyzed in terms of their bright-/ dark field images and the selected area diffraction pattern(SADP) of transmission electron microscopy(TEM).

• Journal of Power System Engineering
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• v.18 no.4
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• pp.85-90
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• 2014

In this paper, the transient thermal and residual stress analysis of the welding of 9% Ni steel plates using the FEA software ABAQUS are presented. The 9% Ni steel plates are welded manually with welding consumables of 70% Ni based Inconel type super-alloys (YAWATA WELD B (M)), producing a multi-pass/multi-layer butt weld. For these materials, temperature dependant mechanical and thermal material properties are used in the analysis. The back gouging is considered in welding process simulation. The FE thermal results are validated by comparing the real fusion profile and heat affected zone (HAZ). In addition, the continuous indentation test was conducted to measure the strength of base metal, HAZ and weld metal.